Adjustable stator for torque converter

ABSTRACT

A torque converter is provided with a stator having adjustable fluid flow holes for changing the K-factor of the torque converter, as needed. The stator includes a base plate with fluid flow openings and an adjustable plate with fluid flow openings. The plates matingly engage, such that the fluid openings are adjacent one another. The degree of overlap of the openings can be varied from fully aligned to substantially misaligned by rotating the adjustable plate relative to the base plate, and thereby controlling the fluid flow through the openings. In alternative embodiments the stator holes can be automatically opened and closed in response to changes in fluid pressure in the torque converter, via reed values or spring biased balls.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of U.S. Ser. No.15/832,234, filed on Dec. 5, 2017, which claims priority under 35 U.S.C.§ 119 to provisional application Ser. No. 62/514,191, filed Jun. 2,2017, all of which are herein incorporated by reference in theirentirety.

FIELD OF THE INVENTION

The invention is directed toward a torque converter having an adjustablestator for controlling fluid flow through the converter orifices, andthereby adjust the K-factor without exchanging a different stator.

BACKGROUND OF THE INVENTION

Torque converters have been known and used in combination with automatictransmissions of automobiles for quite some time. Generally, a torqueconverter consists of a housing, an impeller or pump, a turbine, astator, and a lock-up clutch.

The impeller is hemispherical with an outer wall having inner and outersurfaces, and a plurality of vanes radially mounted to the concave innersurface of the impeller wall. The turbine is rotatably mounted within aback wall, and also contains a plurality of vanes opposite the impellervanes. The impeller wall is welded to the converter body to form anenclosed housing for the torque converter. The stator is located betweenthe impeller and the turbine. The impeller has an input shaftoperatively connected to the engine drive shaft. The turbine has anoutput shaft attached to the transmission input shaft so as to rotatethe output shaft of the transmission.

Many improvements have been made to torque converters to improveoperation and efficiency. For example, see Applicant's patent, U.S. Pat.No. 6,996,978, relating to an improved stator for the torque converter.Also, see the General Motors patent, U.S. Pat. No. 6,959,239, whichdiscloses a cooling control for a torque converter; the Nissan patent,U.S. Pat. No. 7,264,574, which discloses a control device for the torqueconverter lock up; and the Daimlerchrysler U.S. Pat. No. 7,818,965,which relates to augmented output method and apparatus for a torqueconverter.

In use, fluid, such as oil, is added into the torque converter housing.When the engine shaft rotates the impeller, the fluid starts rotating aswell. As the rotation speeds up, centrifugal forces cause the fluid toflow outward toward the impeller vanes. The impeller vanes direct thefluid towards the turbine vanes, wherein the force of the fluid causesthe turbine to rotate in the same direction as the impeller. The turbineshaft rotates the transmission shaft, which causes the vehicle to beginmoving. The orientation of the turbine vanes directs the fluid towardsthe center of the turbine, where the vanes of the stator direct thefluid back towards the impeller, and the fluid cycle is repeated.Initially, the impeller will be rotating at a much greater speed thanthe turbine, which results in energy loss between input from the motorand output from the transmission. However, when the vehicle reaches ahigher speed (typically about 40 miles per hour), the impeller andturbine will be rotating at approximately the same speed. At this time,a lock-up clutch will mechanically connect the impeller and the turbineso that they rotate at exactly the same speed to transfer 100% of thepower through the torque converter.

“Stall” refers to the maximum speed which the motor can achieve againstthe torque converter when the turbine is locked and prevented fromrotating. The revolutions per minute (RPM) achieved is a function of theengine torque and the converter design. Generally, the higher the stall,the less efficient the converter is at high speeds. A high stall torqueconverter allows the engine to get into the power band more quickly. Atorque converter optimized for drag racing will have a much higher stallspeed than a torque converter for a standard street vehicle. Higherstall speeds have lower efficiency, but provides the benefit of aquicker start from a stopped position. On a street car, lower stall isdesired, which improves gas mileage and reduces heat generation.

Ideally, the torque converter for racing should be set up so that thestall speed is close to the RPM at which the engine reaches maximumtorque, so as to provide the greatest initial acceleration.

For example, a drag racing car typically has a stall at 1,500-6,000 RPM.As the RPM increases, the horsepower increases. The higher the torque,the easier it is to start the car moving. Performance engines generallydon't make power until approximately 2,000-3,000 RPM, such that anengine that makes torque at a higher RPM requires a higher stall speedso that the engine is closer to its power band when taking off from thestarting line. Thus, with the vehicle on the starting line and thetransmission brake on, the driver can hit full throttle and the enginewill wind up to peak torque with the car just sitting there, and whenthe transmission brake is released, the transmission engages and the carinstantly launches at close to the peak torque.

The K-factor provides a relative indication of the efficiency of thetorque converter. The K-factor is defined as the engine speed in RPMdivided by square root of the engine torque output.

In the prior art, when it is desired to change the stall speed, it isnecessary to disassemble the torque converter, and substitute adifferent stator having different vanes and openings. This necessitatesan inventory of different stators having various performance designs.For example, a first stator having less vanes and larger openings orwindows has a lower K-factor compared to a second stator having morevanes and smaller openings. The process of changing the stator is timeconsuming, and often must be repeated until the desired K-factor orstalls speed is achieved following repeated testing. Therefore, there isa need for a simpler method and means for quickly and easily changingthe K-factor of a torque converter.

Accordingly, a primary objective of the present invention is theprovision of an adjustable stator for use in a torque converter forvariable K-factor settings.

Another objective of the present invention is a provision of a two-partstator wherein the parts can be slideably moved relative to one anotherso as to vary the size of the oil flow openings in the stator.

A further objective of the present invention is a provision of atwo-part stator which can be adjusted to different sized oil openings byloosening threaded fasteners.

Still another objective of the present invention is the provision of atorque converter stator which is infinitely adjustable to achieve adesired K-factor of a torque converter.

Yet another objective of the present invention is the provision of amethod for varying the K-factor torque converter using a single stator.

A further objective of the present invention is a provision of a methodof changing the K-factor of a torque converter by altering the fluid andflow openings of the stator.

Another objective of the present invention is a method of changing theK-factor of the torque conveyor by adjusting fluid flow through thestator.

Still another objective of the present invention is a provision of anadjustable stator for torque converter which is economicallymanufactured, quick and easy to adjust, and durable in use.

These and other objectives become apparent from the followingdescription of the invention.

The torque converter of the present invention utilizes an adjustablestator which allows the K-factor of the torque converter to be quicklyand easily changed, as desired. This stator includes opposing plateswhich can be adjustably fixed in various positions relative to oneanother so as to alter the size of the fluid flow openings in theplates. The fluid flow openings of the stator can be fully aligned orincrementally offset with respect to one another, thereby changing theK-factor of the torque converter. The plates are joined by fastenersextending through slots in one plate and threaded holes in the otherplate. The fastener can be loosened to rotate the first plate relativeto the second plate, and then tightened to fix the plates in positionwith the desired open area for the fluid flow openings.

SUMMARY OF THE INVENTION

The torque converter of the present invention includes an adjustablestator which allows fluid to flow through the orifices to be controlled,such that the K-factor can be adjusted, without changing to a differentstator. The torque converter includes a base having a plurality of holesand an adjustment plate having a plurality of holes. The base plate andthe adjustment plate are coupled for clockwise and counter clockwiserotation relative to one another, so that alignment of the holes in thebase plate and the adjustment plate can vary from fully open to fullyclosed. The degree or size of overlap between the base plate holes andthe adjustment plate holes determines the fluid flow thereto. Theposition of the adjustment plate relative to the base plate is fixed bya plurality of threaded fasteners which are tightened to secure theadjustment plate in a selected position, and loosened to allow theadjustment plate to be rotated relative to the base plate for changingthe orifice overlap.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a first embodiment of an adjustable stator, from oneside of the base of the two-part stator, according to the presentinvention.

FIG. 2 shows the adjustable plate of the two-part stator, according tothe present invention.

FIG. 3 shows the stator base and adjustable plate in an assembledcondition, with the plate rotated to a first position wherein the baseand plate holes are fully aligned and wide open.

FIG. 4 shows the plate rotated counter clockwise to a second position,wherein the base and plate holes are offset approximately 25%.

FIG. 5 shows the plate rotated counter clockwise to a third positionwith the base and plate holes offset approximately 50%.

FIG. 6 shows the plate rotated counter clockwise to a fourth positionwith the base and stator holes offset or closed approximately 75%.

FIG. 6A shows the adjustable plate rotated to a fifth position, with theholes fully closed.

FIG. 7 shows the base and plate in the second position, with set screwsloosened to allow adjustability of the plate relative to the base.

FIG. 8 is an exploded perspective view of the stator plates of FIGS.1-7.

FIG. 9 is a partial perspective view of a second embodiment of anadjustable stator according to the present invention, and having reedvalves to adjust the K-factor, and the reed valves in a closed position.

FIG. 10 is a view similar to FIG. 9 with the reed valves in an openposition.

FIG. 11 is a perspective of a third embodiment of an adjustable statoraccording to the present invention, and having a ball and detent toadjust the K-factor, with the balls shown in a closed position.

FIG. 12 is a view of the third embodiment with the balls in an openposition.

FIG. 13 is an exploded view of the third embodiment.

FIG. 14 is a schematic showing an engine, a torque convertor, and anautomatic transmission for an automobile.

DETAILED DESCRIPTION OF THE INVENTION

The adjustable converter stator 10 of the present invention includes abase plate 12 and an adjustable plate 14. The stator 10 allows theK-factor of the torque converter to be selectively adjusted, without theneed to interchange multiple stators having different blades oropenings. The stator 10 of the present invention is mounted in thetorque convertor 11 (FIG. 14) in a manner similar to a conventionalstator. However, the stator 10 allows the size of the oil openings to beadjusted without switching out to a different stator.

More particularly, the base 12 includes a plurality of oil holes 16extending in a circle around the center mounting ring 18. The plate 14also has a plurality of oil openings 20 extending in a circle around thecenter mounting opening 22.

The plate 14 is mounted on the base 12, with the mounting ring 18 of thebase 12 extending through the mounting opening 22 of the plate 14. Inthe embodiment shown in the Figures, the base 12 has an inner row oftapped or threaded holes 24 and an outer row of tapped or threaded holes26. The plate 14 includes an inner row of elongated slots 28 and anouter row of elongated slots 30. Threaded screws or bolts 32 (FIG. 7)are adapted to extend downwardly through the slots 28, 30 and into thethreaded holes 24, 26. With the fasteners 32 loosened, the plate 12 canbe rotated clockwise and counter clockwise to adjust the alignment ofthe holes 20 of the plate 14 over the holes 16 of the base 12. Once theplate 12 is in the desired positions, the fasteners 32 are tightened tomaintain the selected position.

As shown in FIG. 3, the plate 14 is rotated clockwise so that thefasteners 32 are at the right end of the slots 28, 30 (as viewed from a6 o'clock position), which fully aligns the holes 16, 20 for maximumfluid flow therethrough. In FIG. 4, the plate 14 is rotated counterclockwise so as to partially close the alignment of the holes 16, 20,approximately 25%. With continued counter clockwise rotation of theplate 14, as seen in FIG. 5, the holes 16, 20 are offset approximately50%, with fasteners 32 being located approximately in the center of theslots 28, 30. Continued counter clockwise rotation of the plate 14 andso that the fasteners 32 are at the left end of the slots 28, 30 (viewedfrom the 6 o'clock position) nearly closes the alignment of the holes16, 20 for minimum fluid flow therethrough.

By adjusting the alignment of the hole 16, 20 and thus the flow of oilor fluid therethrough, the K-factor of the torque converter can beincreased or decreased, without having to exchange stators having adifferent number of vanes, a different pitch of vanes, and/or adifferent size of openings between vanes. Thus, the need for aninventory of different stators is eliminated with a single two-partstator 10 of the present invention.

Thus, the plate 14 can be adjusted relative to the base, to adjust thehole or orifice size to the desired K-factor, and then the screws orbolts 32 tightened to fix the position of the plate 14 relative to thebase 12. Thus, the two-part stator 10 of the present invention replacesthe multiple stators with different numbers of blades and fluid orificesizes, as in conventional torque convertors, thus allowing adjustment ofthe stall speed of the torque converter.

In an alternative embodiment, automatic adjustment of the hole alignmentin the stator 10 may be achieved. For example, a stator with a pluralityof fluid holes is provided, along with a clutch liner to frictionallyengage the turbine of the torque convertor. The holes maybe be closedwhen the vehicle is stationery so as to increase engine speed, withoutfighting the hydraulics of the torque converter. Then, as the vehiclestarts to move, the turbine starts to rotate, the clutch friction isovercome so as to rotate the base to open the fluid holes, therebyincreasing torque efficiency of the convertor.

In yet another alternative embodiment, shown in FIGS. 9 and 10, thestator 10A has slots 16A for passage of oil. Each slot 16A is coveredwith a reed valve 36, such that the slots are closed, as seen in FIG. 9.The reed valves 36 are initially closed when the hydraulic pressure isminimal. As the fluid pressure increases, the reeds 36 move apart fromthe stator slots or openings 16A to increase the fluid flowtherethrough, and thus adjust the K-factor of the torque converter. Thereeds 36 may be attached to the stator 10A in any convenient manner,such as the rivets 38. Thus, one end of each reed valve is fixed to thestator, and the opposite end flexibly extends over the orifice.

In still another alternative embodiment shown in FIGS. 11 and 12, theholes 20 in the upper plate of the stator 10B can be closed by a balland spring detent assembly when the hydraulic pressure is minimal. Thesprings 40, which are seated or fixed in the holes 16 of the base 12,urge the balls 42 upwardly to close the plate holes 20. Then, when thehydraulic pressure increases to a pre-determined value, the spring forceof the springs 40 is overcome so as to unseat the balls 42 with respectto the holes 20, thus increasing fluid flow through the holes, andlowering the K-factor.

Thus, in all embodiments, when the stator holes are closed, the K-factoris relatively high, and as the holes open, the K-factor adjustsdownwardly until the holes are fully open.

The invention has been shown and described above with the preferredembodiments, and it is understood that many modifications,substitutions, and additions may be made which are within the intendedspirit and scope of the invention. From the foregoing, it can be seenthat the present invention accomplishes at least all of its statedobjectives.

What is claimed is:
 1. An adjustable stator for a torque converter of avehicle, comprising: a plate with a plurality of fluid openings; anautomatic adjustment means to open and close the fluid openings tocontrol fluid volume flowing through the openings in response to fluidpressure changes in the fluid openings as engine speed changes; and theautomatic adjustment means initially closing the openings while thevehicle is stationary and then opening the openings after the vehicle ismoving.
 2. The adjustable stator of claim 1 wherein the adjustment meansis a reed valve.
 3. The adjustable stator of claim 1 wherein theadjustment means is a ball detent.
 4. The torque converter of claim 3wherein the ball opens and closes the orifice as the fluid pressureincreases and decreases.
 5. The torque converter of claim 3 wherein theballs open and close the openings as the fluid pressure increases anddecreases.
 6. The adjustable stator of claim 1 wherein the adjustmentmeans is a clutch.
 7. The adjustable stator of claim 1 wherein theadjustment means is set to actuate at a desired RPM.
 8. The torqueconverter of claim 1 further comprising a spring biased ball positionedadjacent each orifice and movable between a seated position relative tothe orifice when fluid pressure increases.
 9. The torque converter ofclaim 1 further comprising a spring biased ball positioned adjacent eachopening and movable between a seated and unseated positions relative tothe opening in response to fluid pressure changes.
 10. The adjustablestator of claim 1 wherein one of the plates has threaded apertures andthe other plate has slots aligned with the apertures and the fastenersbeing bolts extending through slots and into the apertures for securingthe plates together in a selected adjustment position when the bolts aretightened.
 11. The torque converter of claim 1 wherein the orifice sizesare adjustable between fully open and fully closed.
 12. A method ofadjusting K-factor for a torque converter, comprising: orienting fluidflow openings in a pair of mating plates of a stator in the torqueconverter so that the openings are adjacent on another; moving only oneof the mating plates to adjust alignment of the openings from fullyaligned for maximum fluid flow through the openings of the mating platesto fully misaligned to stop fluid flow through the openings of themating plates.
 13. The method of claim 12 further comprising fixing theplates in a selected position.
 14. The method of claim 13 wherein theplates are fixed together using threaded fasteners extending through oneplate and into the other plate.
 15. The method of claim 14 wherein thefasteners are loosened to adjust the plates to vary the opening overlap.16. The method of claim 12 wherein the alignment is adjustable to atleast 50% misaligned.
 17. The method of claim 12 wherein the alignmentis adjustable to at least 75% misalignment.
 18. A method of adjustingfluid flow through a stator of a torque converter, comprising:automatically opening and closing fluid flow openings in the stator inresponse to fluid pressure changes in the fluid flow openings; and thefluid flow openings being initially closed when fluid pressure in thefluid flow openings is below a predetermined value and being opened whenthe fluid pressure exceeds the predetermined value.
 19. The method ofclaim 18 wherein the opening and closing of the openings is provided byflexible reed valves overlying the openings.
 20. The method of claim 18wherein the opening and closing of the openings is provided by springbiased balls overlying the openings.
 21. The method of claim 18 whereinthe adjustment of fluid flow is between fully open to fully closed.